Brucella-specific antibodies of different immunoglobulin classes were quantitatively evaluated with respect to their efficiency in serological tests for bovine brucellosis. IgM reacted more efficiently than IgG1 and IgG2 in both the Rose Bengal plate test and serum agglutination test. The complement fixation test was found to be slightly more sensitive to IgM than to IgG1 and did not react to IgG2. IgM was, however, partly inactivated when heated at 60 degrees C. in the presence of serum.

No abstract

SUMMARYA radioimmunoassay (RIA) has been developed to measure antibodies against Brucella abortus in bovine serum and can be used in the diagnosis of bovine brucellosis. The RIA measures the amount of specific antibody of the IgG1 and IgG2 subclasses but is insensitive to IgM, a characteristic which may make it more suitable than the complement fixation test (CFT) or the serum agglutination test for distinguishing infected animals from those which have been vaccinated with Br. abortus strain 19. The RIA is not subject to prozoning or ambiguous reactions, both of which interfere with the interpretation of the CFT.

No abstract

A total of 1887 bovine sera positive to the Rose Bengal plate test were subjected to other serological tests for bovine brucellosis: the complement fixation test using warm fixation (CFTW),the serum agglutination test (SAT) and the radioimmunoassay (RIA). The SAT was generally much less sensitive than the CFTW. Many sera, however, gave positive reactions in the SAT but no reaction in the CFTW or the RIA. These SAT reactions were attributed to IgM antibody. Comparison between the results of the CFTW and the RIA led to the conclusion that 200 ng could be used as a minimum diagnostic reaction in the RIA.